Crystallographic evolution of microstructure in thin film processing: Part II. Grain boundary structure

The technique of electron backscattered diffraction is used to charactcrize the microtexture and mesotexture of grain neighborhoods in an annealed thin film of Al₉₇Ge₃ on thermally oxidized silicon. Of the microstructural features present in this material, a “sunken” (or “collapsed”) grain neighborhood is examined in terms of its mesotexture. The representation of crystallographic orientation between a “sunken” grain and its surrounding neighbors is assessed using inverse pole figures and Rodrigues-Frank (R-F) space orientation mapping. The two types of mappings are compared and detailed calculations of R-F space are shown. The advantages of the R-F space representation are illustrated. The total number of grains examined is 78 while the number of axis-angle pairs is 72. The microtexture is a strongly preferred < 111> parallel to the substrate normal while the mesotexture is comprised of low angle boundaries and fiber mesotexture as indicated by a R-F map.